The gallbladder is a small pear-shaped sac-like organ found in the right hypochondriac region of the abdomen. Its primary function is to store and concentrate bile. The gallbladder connects with the rest of the biliary system via the cystic duct (Read more!).

The gallbladder lies on the inferior anterior aspect (visceral surface) of the right lobe of the liver in a fossa that is known as the fossa for the gallbladder. This fossa separates the right lobe from the quadrate lobe (Read more!) of the liver.

The gallbladder is approximately 2.76 - 3.94 inches (7 - 10 cm) long, 1.18 - 1.57 inches (3 - 4 cm) wide, and, on average, can store 0.85 - 1.7 oz (25 - 50 ml) volume of bile. In contrast to the liver, the gallbladder does not have a capsule.

The gallbladder is classified as an intraperitoneal organ, and while most of it is surrounded by the peritoneum, the surface facing the liver is not. Therefore, it has an inferior peritoneal surface and superior liver surface. 

Note: The gallbladder is a common cause of abdominal pain due to the formation of gallstones that can block biliary ducts. These stones often can lead to the surgical removal of the entire gallbladder (cholecystectomy).